Why do people fight to keep abstinence-only education when we know that it doesn't work?

My understanding is that this is being pushed by conservatives and religious groups. Do they sincerely believe that this "education" is effective? Or are they so devout that they don't care? Do they not understand that EVERYONE suffers from not educating young people about the responsibilities, dangers, and yes, joys, that come with being ually active? I live in a pretty liberal area (politically and religiously) so sometimes it is hard for me to understand how/why other people think what they think. Any input, ideas, explanations are greatly appreciated. I'm just trying to understand. Thank you for taking the time.